As used herein, the term “mobile terminal” might in some cases refer to mobile devices such as mobile telephones, personal digital assistants, handheld or laptop computers, and similar devices that have telecommunications capabilities. Such a mobile terminal might consist of a device and its associated removable memory module, such as, but not limited to, a Universal Integrated Circuit Card (UICC) that includes a Subscriber Identity Module (SIM) application, a Universal Subscriber Identity Module (USIM) application, or a Removable User Identity Module (R-UIM) application. Any such easily removable data storage component will hereinafter be referred to as a SIM card. Alternatively, a mobile terminal might consist of the device itself without such a module. In other cases, the term “mobile terminal” might refer to devices that have similar capabilities but that are not necessarily transportable, such as desktop computers, set-top boxes, or network appliances.
Calls made to and from mobile terminals are typically controlled by a network operations center (NOC). A NOC is a central location at which information about telecommunications activities for a large number of mobile terminals can be collected, monitored, and analyzed in order to ensure that proper operation of a telecommunications network is maintained. In some cases, in addition to performing these control functions, a NOC may include switching and routing equipment that allows calls to be routed through the NOC. A NOC typically covers a wide geographic area or a large population. For example, two NOCs might cover the United States, while one NOC might cover Canada and one might cover the United Kingdom.
A mobile terminal is typically associated with a single NOC throughout the lifetime of the mobile terminal. That is, a mobile terminal's calls will generally be controlled by the same NOC, even if the user of the mobile terminal travels to an area where another NOC is closer or other circumstances of the use of the mobile terminal change. For example, a mobile terminal might be set up to have its calls controlled by a NOC in the United States. If the user of that mobile terminal traveled to China and placed a call to another user in China, control of the call would pass through the NOC in the United States, even if one or more NOCs were present in China. In some such cases, the mobile terminal might use a Public Land Mobile Network (PLMN) of another operator on a roaming basis.
A mobile terminal might be the ultimate recipient of a call or message, while a NOC might be an intermediary recipient. The mobile terminal to which a message is sent and/or the NOC that controls the message is specified by an endpoint identifier. An endpoint identifier might be an internet protocol (IP) address, a port number, a Uniform Resource Locator (URL), a subscriber identity number, an email address, or some other identifier or combination of identifiers that designate the recipient of a message. The NOC that controls a mobile terminal's calls is specified by an endpoint identifier known as the access point name (APN) of the NOC. The APN of the NOC that controls the calls of a particular mobile terminal might be embedded in the read-only memory (ROM) of the mobile terminal during the manufacture of the mobile terminal. As used herein, the term “manufacture” refers to any assembly and preparation activities performed on a mobile terminal prior to the time the mobile terminal is shipped from the manufacturer. “After the time of manufacture” of the mobile device refers to activities that occur after completion of the assembly of the device by the manufacturer, such as after it has left the manufacturer's facility or factory, or has been shipped to or arrives at the network provider, distributor, point-of sale, or party other than the manufacturer, or is delivered to the customer or user.